The present invention relates to a carburetor for an internal combustion engine, and includes at least one adjusting screw.
DE 30 05 854 C2 discloses a carburetor having screws to adjust the carburetor. These screws are embodied as socket-head cap screws or set screws that are provided with a slot for the application of a tool. The screws are in engagement with threaded bores of the housing. At that end that is opposite the head, the screws are embodied as a cone or a needle. By turning these screws, the cross-sectional areas of fuel nozzles and the idle setting of the butterfly valve of the carburetor can be altered, and hence the fuel/air mixture drawn in by an internal combustion engine through the carburetor can be regulated. Such carburetors are preferably utilized with two-stroke internal combustion engines for manually guided implements, whereby an adjustment of the carburetor is required as a function of carbon monoxide and speed when the internal combustion engine is running.
To adjust the carburetor, fully automatic adjustment and measurement compartments are used into which the adjustment screws on the carburetor are moved and rotated by automatically controlled adjustment knobs using an adjustment tool. With the known slotted screws, an adjustment tool can often only be brought into engagement with the screw slot after passing through a large angle of rotation. The screw slots are not suitable for centering the tool. In addition, the known socket-head cap screws, due to the fact that their heads are formed by swaging or other deformation, are not true to shape, which can be a drawback with regard to the precision of adjustment of the fuel nozzles.
It is therefore an object of the present invention to provide a carburetor that has at least one adjusting screw and that enables a precise rapid adjustment of the carburetor.